The mob attacked the police with sticks and stones when the cops asked them not to go for a blockade at Gopal Nagar, here, in protest against alleged police inaction in finding a local youth who was missing since February 21, they said.
After three policemen got injured in the attack, cops resorted to lathi-charge to disperse agitating crowd.
Local people alleged that several people were injured in the lathicharge but it was yet to be confirmed.
The case was taken over by the CID and one person was arrested but the youth was yet to be traced.
Local people had blockaded a key road sometimes ago also on the same issue, the police said.